/*
 * Copyright 2006-2015 Transsion.com All right reserved. This software is the confidential and proprietary information
 * of Transsion.com ("Confidential Information"). You shall not disclose such Confidential Information and shall use it
 * only in accordance with the terms of the license agreement you entered into with Transsion.com.
 */
package com.yunji.framework_template.common.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * ClassName:CaptchaUtil <br/>
 * 关于验证码的工具类 Date: 2016年8月18日 下午4:27:28 <br/>
 * 
 * @author lyndon
 * @version
 * @see
 */
@SuppressWarnings("restriction")
public final class CaptchaUtil {

    private CaptchaUtil(){
    }

    /*
     * 随机字符字典
     */
    private static final char[]             CHARS      = { '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
                                                           'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R',
                                                           'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
    public static final Map<String, String> captchaMap = new HashMap<String, String>();
    /*
     * 随机数
     */
    private static Random                   random     = new Random();

    /*
     * 获取4位随机数
     */
    private static String getRandomString() {
        StringBuffer buffer = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            buffer.append(CHARS[random.nextInt(CHARS.length)]);
        }
        return buffer.toString();
    }

    /*
     * 获取随机数颜色
     */
    private static Color getRandomColor() {
        return new Color(255, 255, 255);
    }

    /*
     * 返回某颜色的反色
     */
    private static Color getReverseColor(Color c) {
        return new Color(255 - c.getRed(), 255 - c.getGreen(), 255 - c.getBlue());
    }
}
